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Reverberation Level Modeling via Coupled Mode Approach in Shallow-Water Sound Channel with Internal Solitary Waves

Department of Naval Architecture and Ocean Engineering, Seoul National University, Seoul, Korea

Department of Naval Architecture and Ocean Engineering, Research Institute of Marine System Engineering, Seoul National University, Seoul, Korea

E-mail Address: wseong@snu.ac.kr

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Youngmin Choo

Department of Defense Systems Engineering, Sejong University, Seoul, Korea

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https://doi.org/10.1142/S2591728518500457Cited by:2 (Source: Crossref)

Abstract

Reverberation level (RL) is modeled in a shallow water environment with an underwater sound channel and internal solitary wave (ISW) using the coupled mode method. Numerical RL result based on one-way coupled mode shows an abnormal increase when a source is located near the channel axis and the ISW is located far from the source. The abnormal increase is analyzed by using a two-mode approach (assuming a trapped mode and a bottom interacting mode). The two-mode approach explains the relation between the RL increase and the ISW location explicitly: the ISW transfers trapped mode energy to bottom interacting mode energy, and its increasing rate is a function of its modal attenuation and ISW location from the source. The sensitivity test according to several ISW parameters is also performed.

Keywords:

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